npm Script Exit 127 "command not found" - Fix Missing Tool in CI

Exit code 127 from a shell means "command not found". When an npm script calls a tool that is not installed, not a local dependency, or not on PATH, the script aborts with 127.

What this error means

An npm run <script> step fails with sh: 1: <tool>: not found and exit code 127. It typically works locally (where the tool is globally installed) but fails in CI, where only declared dependencies are present.

npm output

> app@1.0.0 build
> some-cli --out dist

sh: 1: some-cli: not found
npm error code 127
npm error command failed

Common causes

The tool is not a project dependency

The script relies on a globally-installed binary present on your machine but absent in CI. A clean install only provides declared dependencies, so the command is missing.

The binary is not on PATH

A locally-installed dependency’s binary lives in node_modules/.bin. npm scripts add that to PATH, but a directly-invoked subshell or wrong working directory can miss it.

How to fix it

Add the tool as a dependency

Declare the binary so a clean install provides it, and npm puts it on the script PATH.

Terminal

npm install --save-dev some-cli
# now "some-cli" resolves via node_modules/.bin inside npm scripts

Invoke local binaries correctly

Call the tool from an npm script (not a bare subshell) so .bin is on PATH.
Or use npx some-cli to resolve the local/temporary binary explicitly.
Confirm the script runs from the package root where node_modules exists.

How to prevent it

Declare every tool a script uses as a dependency.
Run tools through npm scripts or npx, not globals.
Keep the working directory at the package root.